Release 4.1: DB_ENV->memp_sync

In addition, if DB_ENV->memp_sync() returns success, the value of
lsn will be overwritten with the largest log sequence number
from any page that was written by DB_ENV->memp_sync() to satisfy this
request.

This functionality was never correctly implemented, and has been removed
in the Berkeley DB 4.1 release. It is very unlikely application programs used
this information. If your application used this information, please
contact us for help in upgrading.